1. Field of the Invention
Embodiments of the present invention are generally related to the field of location aware computing. More particularly, embodiments of the present invention are related to the conservation of power on a mobile device through motion awareness.
2. Description
Many mobile device capabilities require the device to know where it is located. Two such capabilities include always best-connected computing and location-aware computing. In the case of always best-connected computing, one common practice for keeping a device online as it roams is to scan the air for received RF (radio frequency) signals and then use the resultant information to determine which cell towers, Wi-Fi (Wireless Fidelity) access points, or Bluetooth devices are nearby in order to make connection decisions. Location-aware computing may also use RF signal information or received Global Positioning System (GPS) satellite data to compute and track the device's current location. Both of these capabilities consume precious battery power.
Currently, motion models may be used with always best-connected computing and location-aware computing activities to combat the power drain problem on the mobile device. Motion models often throttle back the always best-connected and location-aware computing activities when the mobile device is determined to be moving slowly or not moving at all and then ramp them back up when the motion model believes that the mobile device is moving again. However, with no other inputs besides the information from the always best-connected and location-aware computing activities to determine when the mobile device is moving again, the motion model is little more than a feedback loop with a negative implication of reducing its accuracy whenever it reduces power consumption. Since scanning and GPS tracking are essentially polling activities, power savings are accomplished by lowering the measurement duty cycle, i.e., scanning less frequently. At lower power states, a lag between actual motion and detection of that motion during the next duty cycle is introduced, thereby artificially establishing a floor for power savings below which this imprecision becomes unacceptable.
Thus, what is needed is a method and apparatus for conserving power on a mobile device through motion awareness that eliminates scan-polling or GPS tracking when the mobile device is stationary. What is also needed is a method and apparatus for incorporating another input to the motion model that determines whether the mobile device is stationary or moving independent of the information from the always best-connected and location-aware computing activities.